Abstract

An indirect passive solar dryer was designed, constructed and tested. The dryer was designed to accommodate a total quantity of 45 kg and was tested by carrying out three experiments with fresh cassava chips of approximate sizes of 2.5, 3.0 and 3.5 cm. The highest temperature recorded during the experiments was 60.5°C. The average result shows that the 3.0 cm chips inside the drying chamber were dried from 65% (187% dry basis) to 10% (11% db) moisture content in 4 days, while the samples outside the chamber were dried to 11% (13% dry basis) in 6 days. This result shows that over thirty percent saving in drying time was achieved in the dryer compared to the open sun drying. The calculated drying efficiency and the Pick-up efficiency of the dryer are 31 and 58% respectively. The organoleptic quality test of the dried cassava chips showed that samples in the dryer retained their white colour, thus, indicating no mould growth.

Key words: Cassava, chips, dryer, solar-drying, storage.